Ten Nobel Peace Prize winners are appealing to Saudi Arabia’s king and crown prince to show mercy and halt the executions of 14 young people sentenced to death for participating in protests in 2012.

In a letter released on Friday they said staying the executions would “correct a great injustice”.

The laureates said the 14 were convicted and sentenced in a mass trial “based on the actions of the worst defendant”, arguing that several would never warrant the death penalty.

They also accused Saudi authorities of coercing confessions and reportedly subjecting the protesters to physical force. The 14 face execution for protests and violence against security forces.

Among the 14, all minority Shiite Muslims, is Mujtaba al-Sweikat, who was detained at an airport on his way to attend Western Michigan University.

The laureates said Sweikat was 18 when he was arrested on charges including supervising a group on Facebook and photographing the demonstrations. The letter said Sweikat’s shoulder was broken while his confession was being coerced.

Others facing execution include Ali al-Nimr, charged with setting up a Blackberry page named “The Liberals” and posting photos of the demonstrations and inviting people to participate; Munir Adam, a partially deaf and blind 20-year-old; and two others who were juveniles, the ten laureates said.

The Nobel laureates said that in court, the defendants repudiated their confessions. The letter also said that during the appeals process, the allegations of physical coercion were reportedly not investigated.

A spokesman for the Saudi Ministry of Justice said in a statement published August 4 that all defendants in Saudi Arabia receive due process.